I have a Nitro Z7 that has the same design flaw with the middle seat coming loose, etc.
There is a guy that makes a diamond plated piece specifically for the Z7 attaching exactly where the seat attaches, thus making it a step. You can always put the seat back on when you need it. He sells the part for $50, it looked really nice, perfect fit. The Bass Pro Shop in Clarksville IN had a few on hand. You might be able to contact them and work something out if you want one. None of the other BPS stores have it, it's not something they get from a vendor, it's someone local.
There is a guy that makes a diamond plated piece specifically for the Z7 attaching exactly where the seat attaches, thus making it a step. You can always put the seat back on when you need it. He sells the part for $50, it looked really nice, perfect fit. The Bass Pro Shop in Clarksville IN had a few on hand. You might be able to contact them and work something out if you want one. None of the other BPS stores have it, it's not something they get from a vendor, it's someone local.